Photometer 2 Instruction Manual
DLGelectronics.com
10
TECHNICAL AND PERFORMANCE DATA
The information contained in this section is for guidance only and represents typical,
rather than the guaranteed minimum performance. It is provided for the guidance of
specialist users with unusual applications and may be disregarded by the majority of
users.
Calibration
The meter has been calibrated to give a negative tone in the centre of the useable
range. Film tests have been carried out to determine the optimum point. See figure.
Note that the film base is not perfectly transparent and typically transmits around 50% of
the light. The test data has been adjusted accordingly, to give 0% for the lightest
possible (around 50% transmission) negative and 100% for a completely opaque
negative.
Measured HP5+ Characteristic
-3
-2
-1
0
0
1
2
3
4
5
Log Relative Exposure
L
o
g
Int
ensit
y
Film Base
Calibration Point
